Papers by Algirdas Pakstas
Anais do IV Simpósio Brasileiro de Arquitetura de Computadores e Processamento de Alto Desempenho (SBAC-PAD 1992)
For many years software engineers have been providing the engineers of other fields with advanced... more For many years software engineers have been providing the engineers of other fields with advanced design tools. But the tools used by software designers themselves look quite primitive in comparison. Only CASE-like systems developed during last years can provide reasonable help to software developers. Experimental software development systems ALADDIN/LAMP is oriented to creation of distributed computer control systems (DCCS). Proposed approach to development distributed software configurations (DSCs) is based on the model of virtual distributed software configuration (VDSC) with information-transport ports (ITPs) as interconnecting servers. Transputer networks and OCCAM-written software are often used for creation of DCCS. An approach to ALADDIN/LAMP tools-extention for OCCAM-written DSCs handling is discussed in this paper. Survey of tools is presented (OCCAM-oriented structure editor OSE, OCCAM structure extractor OSX, ALADDIN/OOB translator and deadlock locator and analyser DLA)....
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Computer network technologies have been growing explosively and the study in computer networks is... more Computer network technologies have been growing explosively and the study in computer networks is being a challenging task. To make this task easy, different users, researchers and companies have developed different network modelling and simulation (MS) tools. These network MS tools can be used in education and research as well as practical purposes. They vary with their characteristics. This paper reviews some of the most important network MS tools developed recently. This paper also shows a classification of the tools used in communications networks.
cms.livjm.ac.uk
Comparisons between Computer network simulation tools' models are demonstrated in this papers. An... more Comparisons between Computer network simulation tools' models are demonstrated in this papers. An integrated tool NeDaSE (network design and simulation environment) has been implemented and using this integrated tool, models are transformed between different network simulationt tools and a comparison between codes of the network models of tools is preformed. The models representation codes of the tools are characterised in this paper. This is the continuation of our previous papers.
2007 15th International Conference on Software, Telecommunications and Computer Networks, 2007
WLANs are different from the traditional wired LANs in terms of their exposure to potential threa... more WLANs are different from the traditional wired LANs in terms of their exposure to potential threats, vulnerability and security techniques. Intrusions to WLANs are facts of the everyday life and handling them becomes more and more difficult. Currently there is no standardised reference model which may help to design, compare and evaluate the existing or future Intrusion Handling Systems (IHSs1) for WLANs. Analysis of the commercial IHSs shows that they all are built as a proprietary systems which are neither taking into consideration existence of other IHSs nor they are trying to find the ways to establish inter-IHS collaboration which may help to achieve better security for the end-users. Hence this paper starts by an analysis of the features of existing IHSs for WLANs, followed by proposing the new ways to enhance their design, and then discussion of development of such a novel reference model for a scalable distributed IHS architecture.
SN Computer Science
Computer networking is taught for some time at universities. A network is a complex mix of applic... more Computer networking is taught for some time at universities. A network is a complex mix of applications, communications protocols and link technologies, traffic flows and routing algorithms. Teaching the networking concept, the network design process is a challenging task, requiring designers to balance user performance expectations with costs and capacities. One of the obvious approaches employed to deal with its complexity is through the use of modelling and simulation techniques. This paper examines three best educational tools that can be used in the Computer Networking course at Cardiff Metropolitan University or any University for educational purpose. The paper demonstrates that a successful teaching programme needs to combine a range of teaching tools to achieve its aims. Analysing various aspects of the course provides evaluation of the overall success of the tools. Many network design and simulation tools have been studied. Based on our research and experiment, the best edu...
LNSE, Aug 2, 2016
Software Quality Assurance (SQA) becomes one of the most important objectives of software develop... more Software Quality Assurance (SQA) becomes one of the most important objectives of software development and maintenance activities, and many SQA standards have emerged as part of the Software Engineering discipline. However, despite the effort made to improve consistency and coherency among SAQ standards, still there is no single standard that covers the whole SQA knowledge area. To contribute to this effort, this paper presents a framework of an ontological model to describe and define both domain and operational knowledge of SQA. International standards (SWEBOK, IEEE, and ISO) were the main sources of the terminology and semantic relations of the proposed SQA conceptual model. Different approaches have been used to evaluate the developed SQA ontology. The ultimate goal was to develop an ontology that faithfully models the SQA discipline as practiced in the software development life cycle.
IFAC Proceedings Volumes, 1990
Abstract Automation of the development of distributed software configuration (DSC) in the distrib... more Abstract Automation of the development of distributed software configuration (DSC) in the distributed computer control systems (DCCS) is discussed. The present paper deals with the building technology of the Organization of the interactions environment of application programs through the constructions like Information transport port" (ITP). On the basis of the DCCS structural model the system architects' language ALADDIN is developed. It is designated for the control of ITP work and for the linkage of DSC. The ALADDIN/LAMP software development system is described.
Intrusive attacks to WLANs is pervasive nowadays and combating them is becoming more and more dem... more Intrusive attacks to WLANs is pervasive nowadays and combating them is becoming more and more demanding. Currently there is no standardized reference model which can be used to compare and evaluate existing or design future Intrusion Handling Systems for WLANs. Hence, this paper describes and discusses the construction of Response Subsystem Modelling Ontology and Management Console Ontology for Intrusion Handling System reference model. The proposed ontology is based on the concepts of various ontology modelling and simulation tools. This gives careful attention to support two important functions, that is to manage the dependencies between ontologies and at the same time to keep and restore their consistencies if they alter in order to accommodate new information, or to adjust the representation of the domain as the world changes.
Most lawyers, economists and policymakers who pontificate on Internet governance lack an adequate... more Most lawyers, economists and policymakers who pontificate on Internet governance lack an adequate understanding of (a) the Internet's architecture and engineering, (b) Internet mechanisms, (c) institutions involved in Internet governance, (d) the governance of those institutions, and (e) processes involved in Internet governance. This talk is discussing these and related issues.
Communications in Computer and Information Science, 2016
Informaticalt, 2000
Growing popularity of the mobile code requires to consider various aspects related to its securit... more Growing popularity of the mobile code requires to consider various aspects related to its security. In the aviation industry there is a case when additional information needs to be delivered to the pilot by uploading it from the ground station. It creates a need for a platform-independent solution and it raises a problem of the mobile code security as well. Organization of the security in the Base System (similar to extranets) as well as the security issues of the mobile code (or safelets for use in the aircrafts) delivered to the Remote Platform are discussed in the paper. Safelet implementation technologies and issues of code effectiveness and safety itself are discussed with Java and Juice/Oberon technologies been compared.
The intensity of long-range dependence (LRD) of the communications network traffic can be measure... more The intensity of long-range dependence (LRD) of the communications network traffic can be measured using the Hurst parameter. There are various estimators of Hurst parameter which differ in reliability of their results. Getting reliable estimator can help to improve traffic characterization, performance modelling, planning and engineering of the real networks. This paper deals with the comparison of a few Hurst parameter estimators in standardized simulation experiment generating synthetic data sequences that exhibit long-range dependent features corresponding to observed data. The two best known classes of stationary processes with slowly decaying correlations (i.e., having long-range dependence) have been studied: fractional Gaussian noise (fGN) and fractional autoregressive integrated moving-average (FARIMA). Earlier authors introduced the estimator called "Hurst exponent from the autocorrelation function" (HEAF) and in this work it is compared with an estimator based on the FARIMA process (FARIMA-H). Approximately unbiased versions are constructed and compared by simulation. 0.8786, 0.9066
For the compilation of the edited video stream, normally at least two others are manipulated (A/B... more For the compilation of the edited video stream, normally at least two others are manipulated (A/B roll). With conventional "linear editing", video/audio sequences are stored on the magnetic media with compilation via replication in real time. This causes some limitations in flexibility, since final compilation must be in the correct chronological sequence and is constrained by the serial linear tape access time. "Non-linear editing" systems require all clip/sequence data to be stored on the random access medium, which affords play-out and manipulation/compilation abilities. Digital formats afford the opportunity for non-linear editing but certain constraints must be considered. Volume of data associated with audio and video streams is very large and requires high capacity storage. While adequate storage is often available, the communications between the workstations and access to the storage becomes a bottleneck. Paper is devoted to investigation of the existing experience of building Distributed Digital Video Editing Systems and use in them widely available computing platforms such as PCs in order to apply this for the project DIVIDEND (DIgital VIDeo Editing based on the Network testbeD). Project DIVIDEND addresses the demand of the media industry and video producers in particular, for non-linear editing facilities which are currently unavailable. It intends to build an experimental testbed based on high speed network technology called Dynamic synchronous Transfer Mode (DTM). System architecture and specifications characteristics are described.
2006 International Conference on Intelligent Engineering Systems, 2000
Uploads
Papers by Algirdas Pakstas